Mobile Q&A site ChaCha has laid off most of its employees, saying it came up on the losing side of an algorithm change by Internet powerhouse Google.

The Carmel tech company laid off 26 of its 42 employees Friday and Monday, leaving it with a skeleton staff of 16 people at its offices in Clay Terrace retail and office center. Its Los Angeles sales office also was closed.

Carmel entrepreneur Scott Jones, who co-founded ChaCha in 2006, said the cuts were prompted by a drastic drop in advertising revenue after Google reduced ad rates for ChaCha-directed ads about 10 days ago.

"Rates were one-fifth" what they formerly were, Jones said Monday. "It made it completely upside down" to run the business. "We tried to fix it. But we couldn't move the needle, and so we made the cutbacks across the board."

ChaCha, like many online media companies, depended on Google AdSense for a majority of its ad revenue, Jones said. So the change in Google's algorithms that had the effect of cutting ad rates for online ads viewed on ChaCha's website was devastating.

Jones said he tried to get an explanation from Google about the change but wasn't satisfied with the company's response. "Google black-boxes everything and doesn't tell their partners anything. That's their tradition."

A spokesman for Google, which is based in Mountain View, Calif., said, "We don't have any details" on Jones' charge that Google was behind the drop in ad revenue to ChaCha. "We're looking into it."

The spokesman said that Google made 890 changes to its search algorithms last year that could have affected revenues to websites. But a website's ad revenues also are affected by many other factors, the spokesman said, such as differences in the ways people search for things online and changes that other online companies make to their websites.

Several years ago, a similar algorithm change at Google also led to an ad revenue drop at ChaCha, but the company responded by creating a "social reactor" division that managed to enhance traffic to ChaCha's website from social media, resulting in rising ad revenue over time, Jones said. Most of those laid off worked in the social reactor division.